User:Paulochieng70/sandbox

RHEUMATIC FEVER/HEART DISEASE (RHD)

Rheumatic fever is an inflammatory disease that occurs in children and young adults( first attack usually occurs between 5 and 15 years of age) as a result of pharyngeal infection with group A streptococci. It affects the heart, skin, joints and CNS. The pathophysiology of RHD involves pharyngeal infection with group A streptococcus which may then be followed by clinical syndrome of rheumatic fever. This is thought to develop because of an autoimmune reaction triggered by molecular mimicry between M proteins of infecting streptococcus pyogenes and cardiac myosin and laminin. The condition is therefore NOT due to direct infection of the heart or to the production of toxin. Chronic and progressive valvular heart disease follows in more than half those affected. In RHD, all the three layers of the heart may be affected. The characteristic lesion of rheumatic carditis is the Ascholf nodules, which is a granulomatous lesion with a central necrotic area occurring in the myocardium of the left ventricle. Small, warty vegetations may also develop on the endocardium, particularly on the heart valves. This leads to some degree of valvular regurgitation. A serofibrinous effusion characterizes the acute pericarditis that occurs.